Bowser's Sinister Slots is a Bowser minigame appearing in Mario Party 10. It is one of the extended minigames that do not appear at normal times; rather, it appears as one of the minigames that Bowser can choose when he gets angry or he enters Big Bad Bowser Mode. This minigame is set in a place with two trains, where Bowser is seen pulling the lever of the slot machine attached to the train before the minigame starts.
The minigame takes place in The Bowser Express from Super Mario 3D World. Bowser, controlled by the , has to press the button on the bottom of the slot machine, which shows faces of each Team Mario character. When all three buttons are pressed, the Bill Blaster on the bottom will fire Bullet Bills on targeted characters. When three same characters are chosen, Bowser will fire nine Bullet Bills on a targeted character. Other players, controlled by the Wii Remote, must avoid Bullet Bills so that they can avoid losing their hearts. If any players lose all their hearts, they can still be selected on the slot machine by Bowser. However, the Bullet Bill will not target that player; it will just fly straight. If Bowser depletes all the team players' hearts before time runs out, he wins; otherwise, the team players win.
